"If you're talking about surgery, you're typically talking about a patient who is a hundred pounds or more overweight," Jones said.

Keane hoped to lose at least 100 pounds for good.

He chose the laparoscopic gastric sleeve, a relatively new procedure that's now more popular at Beth-Israel than a gastric bypass or lap band.

"It takes a large stomach, say the size of cantaloupe, and trims it down to the size of a banana," Jones explained. "And as you cut the stomach down to size, you eat a little bit of food and you're full."

After surgery, Dr. Jones said his patients report fewer signals to the brain telling them to eat.

"And so it makes it easier to sort of go, OK, it's breakfast, it's lunch, it's dinner," he said. "Not, I'm starving! What's in the fridge?"

Sixteen months later, Keane is nearly half the man he used to be.

"One-hundred-thirty-five pounds so far," he announced, smiling.

In some ways, Keane is also twice the father for his kindergartner, Emily.

"She's mentioned it several times," he said. "My dad's a lot skinnier now. My dad eats a lot healthier. Just being able to, you know, get down on the floor to play with her or run around outside for an hour, half-hour. I'm just amazed at how much easier those small tasks are now.

He said he has more energy for a busier life, which now includes CrossFit sessions four to six times per week.

"I feel like Jeff's at a place where this is it for him," observed his wife, Mary, as she looked at her husband. "This is the new Jeff. I guess I get emotional because I know you'll be here a lot longer."

For extra motivation, Keane said he's held on to some of the clothes he used to wear.

"I'm just always so amazed to look at those clothes and say that I fit in those," he said. "So no, I never want to go back there again."

Jones cautioned that surgery is not a quick fix for obesity.

Patients like Keane still have to exercise and eat healthy to keep off the weight long-term.